lcb_respexists_is_found returns true for documents which have been removed

If you upsert a doc, and then remove it at some point later, you will get LCB_ERR_DOCUMENT_NOT_FOUND. But, if you see if it exists after that, the lcb_respexists_is_found actually still returns true. Looking at the exists.cc, things look reasonable. Perhaps a document that has been removed recently still exists (marked as deleted) and we end up with LCB_SUCCESS in the rc for those?

This is really on latest master (though I marked it as 3.0.0, it is later than that)